Diazotype reproduction materials



Nov. 17, 1964 J. KOSAR 3, 3

DIAZOTYPE REPRODUCTION MATERIALS Filed March 19, 1965 FIG.|

HEAT-DEVELOPABLE TWO-COMPONENT PHOTO- SENSITIVE DIAZOTYPE LAYER I2suPPoRT HEAT-DEVELOPED TWO-COMPONENT PHOTOSENSITIVE DIAZOTYPEREPRODUCTION MATERIAL IO FIG.2

L E 22 DIAZOTYPE LAYER 23 SUPPORT 2| HEAT-DEVELOPABLE TWO-COMPONENTPHOTOSENSITIVE DIAZOTYPE REPRODUCTION MATERIAL 2O NG SHEET 3OBASE-RELEASING SUPPORT 3 I AGENT 32 BASE-RELEASING AGENT 32TWO-COMPONENT PHOTOSENSITIVE DIAZO- TYPE LAYER 42 SUPPORT 4|TWO-COMPONENT PHOTOSENSITIVE DIAZOTYPE REPROQUCTION MATERIAL 4OINVENTOR. JAROMI R KOSAR 8 AT ORNEY United States Patent 3,157,593BIAZGTYPE REPRGDUCTIGN MATEREALS .laromir Kosar, Eeechhurst, N.Y.,assigns: to gsser Company, Hoholren, N.J., a corporation of New erseyFiled Mar. 19, 1953, Ser. No. 266,231 9 (Cl. %4)

This invention relates to diazotype reproduction mat rials and tomethods for their preparation and use, and refers more particularly toheat-developable two-compo nent photosensitive diazotype reproductionmaterials and methods for their preparation and use.

Diazotype reproduction materials are Widely used commercially because oftheir combined advantages of quality and low cost. Two types aregenerally used: the semiwet developing type and the dry developing type.Each has its own inherent disadvantage. In the case of the semi-wetdeveloping type, the handling of a liquid developer is a negativefactor. For the dry developing type, the machine requirements forconfining and exhausting noxious ammonia fumes are negative factors. Inaddition, the loading of concentrated ammonia water and the removal ofspent ammonia water from the machine are disagreeable tasks in the dailyuse of dry developing machines.

Thermographic reproduction processes have been used to avoid oreliminate some of the disadvantages of the diazotype processes, but theypossess other objectionable properties such as the retention ofsensitivity to heat even after the desired reproduction has been made.In addition these materials are not necessarily photosensitive.

The present invention combines the advantages of the diazotype processwith that of the thermographic process While avoiding some of thedisadvantages of both. The quality and low-cost of the diazotype processis combined with the simplicity of development of the thermographicprocess. The use of liquid developers and gaseous ammonia is avoided,and the final reproduction is insensitivejo further application of heat.

Therefore one object is to provide a heat-developable photosensitivediazotype reproduction material which does not have the disadvantages ofthe prior art.

Another object of the present invention is to provide a heat-developabletwo-component photosensitive diazotype reproduction material.

Another object is to provide a diazotype reproduction material which isdevelopable without the use of liquid developers or gaseous ammonia.

Another object is to provide a heat-developable reproduction materialwhich, after development is stable to further undesirable developmentdue to the application of heat.

Another object is to provide a method for the preparation ofheat-developable two-component photosensitive diazotype reproductionmaterial.

Another object is to provide a method for the use of heat-developabletwo-component photosensitive diazotype reproduction material.

Another object is to provide a developing sheet for the heat-developmentof a two-component photosensitive diazotype reproduction material.

Another object is to provide a method for the use of a developing sheetin the heat-development of a two-component photosensitive diazotypereproduction material.

Another object of the present invention is to provide a reproductionmaterial which has good quality and low cost.

Other objects will become evident during the course of thespecification.

In the drawings:

FIGURE 1 is a sectional view of a heat-developable ice two-componentphotosensitive diazotype reproduction material 16 comprising a support11 and a heat-developable two-component photosensitive diazotype layerlZcoated on said support. FIGURE 2 is a sectional view of aheat-developable two-component photosensitive diazotype reproductionmaterial 29 comprising a support 21, a precoat layer 22 coated on saidsupport, and a two component photosensitive diazotype layer 23 coatedover said precoat layer on said support.

FIGURE 3 is a sectional view of a developing sheet 36 comprising asupport 31 and a base-releasing agent 32 impregnated in said support incontact With a two-component photosensitive diazotype reproductionmaterial 40 comprising a support 41 and a two-component photosensitivediazotype layer 42 coated on said support.

The tollowin is a group of chemical structural formulas of thethermosensitive base-releasing agents of the present invention:

Hexamethylenetetrarrine N Thiosemicarbazide NI-l -CSNHNH Semicarbazidehydrochloride NH NHC O-NH HCl Carboxymethyl trimethyl ammonium chloridehydrazide NH NHCOCH N( CH C1 Carbohydrazide NH NHCONHNH SuccinhydrazideI Ii-I NHCO-CH CH -COOH Acetone semicarbazone (CH C' 1 INHC O-NHBriefly, it has been found that base-releasing agents can be used todevelop the latent image on a two-cornponent or dry developing type ofdiazotype reproduction material. The base-releasing agent can beincorporated into the sensitized layer, into a separate precoat layerbetween the support and the sensitized layer, or it can be impregnatedinto a separate support to make a developing sheet. Compatibility withthe other chemicals in the sensitizing solution determines Whether ornot it can be incorporated into the various systems. Generally where itis incorporated with the sensi izing solution adjustments are requiredto prevent precoupling of the diazonium compound and the coupler. Baseis released under the influence of heat.

be included with the chemicals in the sensitizing'solution if hiscompatible with the chemicals. In cases where minor adjustments cannotbe made to accommodate the base-releasing agent in the sensitizingsolution,

' the agentcan either be coated on the same support in a precoat layerbetween the support and the sensitizing layer or it can ,be coated orimpregnated into a separate support to form a developing sheet.

The base-releasing agents found to be suitable for the present inventionare organic nitrogen compounds such 'as hexamethylenetetramine,thiosemicarbazide, and combinations of these with other organic nitrogencom,- pounds. Combinations of hexamethylenetetramine with semicarbazidehydrochloride for example were found to be satisfactory for purposes ofthe present invention.

' The use of heat-developable two-component photosensitive diazotypereproduction materials with the base releasing agent in either thesensitizing layer or a precoat layer is the same. Both are exposedconventionally through a master to actinic radiations to form latentimages in the reproduction material. the master, both can be heated inthe temperature range between the heat activation temperature of thethermosensitive base-releasing agent and the scorchingtemperature of thereproduction material support. Temperatures of about 140 to 160 C. havebeen found to be adequate for development purposes.

In the case of a developing sheet, the developing sheet is placed inface-to-face contact with van exposed twocomponent photosensitivediazotype reproduction material and. the assembly heated preferably fromthe developing sheet side. The heat releases the base from thebase-releasing agent and the base migrates to the exposed diazotypereproduction material and thus permits coupling to take place.Reproduction of the original image is thus effected.

The invention is further illustrated by the following examples which arenot intended to limit the scope of the invention.

' EXAMPLES Example 1 A support was coated with a sensitizing solutionprepared according. to the following formula:

After drying, the sensitized support was exposed to actinic radiationsthrough a master and then heated at 160 C. for a few seconds. Ared-violet image corresponding to the master image was produced on ayellow background.

Example 2 Hexamethylenetetramine was used in the following formula tomake a precoat solution:

Water ml 150 Hexamethylenetetramine g .Trichloroacetic acid g 5 Water ml150 1,3,6-naphthalene trisulfonic acid, sodium salt g 3 Tartaric acid g/z p-Dimethylarnino benzene diazonium chloride, zinc I chloride salt a g4 .2,3 dihydroxynaphthalene dsulfonic acid, sodium salt g 5 Thiourea g r6 Zinc chloride -Q. g 1

After removal of This was coated on a support and dried. The precoatedAfter drying, the sensitized precoated support'was exposedand developedas "in Example 1 to produce a dye' image corres onding to the masterimage.

Example 3 Hexamethylenetetramine was used in the following solution toprepare a developing sheet:

Water m1 150 Hexaznethylenetetramine g 1 This solution was used toimpregnate an absorbent support. After drying, the impregnateddeveloping sheet was used redevelop an exposed diazotype material byplacing the developing sheet in uniform contact with the exposedsensitized surface of the diazotype material, and heating for 4 secondsat C. 'An; image corresponding to the master image was produced on thediazotype material. Greater amounts of hexamethylenetetramine in theimpregnating solution improved the Example 4 Asensitizing solution wasprepared according to the following formula: V

Water v Hexamethylenetetramine gu V l Trichloroacetic acid Q; g 51,3;6-napl1thalene trisulfonic acid, sodium salt g 6- Semicarbazidehydrochloride g 4 p-ethyl-hydroxyethyl-amino benzene diazonium chloride,zinc chloride salt g 4 2,3-dihydroxynaphthalene G-sulfonic acid, sodiumsalt L; g 5 Thiourea g 7 Zinc chloride g 4 This solution was coated ontoa support and dried. It was then exposed under a master to actinicradiations, and developed by heating at C. for 6 seconds. A violet imagewith a white background was produced.

Example 5 V A 'precoat solution was prepared according to the followingformula:

Water ml 150 Hexamethylenetetramine g 1 Semicarbazide hydrochloride g 4This was used to precoat a support. After drying, the precoated supportwas then sensitized with a solution pre pared according to the followingformula:

salt

Thiourea g 7 Zinc chloride 5 4 Thiosemicarbazide e 10 This solution wascoated onto a support and dried. It

A stock solution was prepared according to the following formula:

Water ml 1,050 Hexamethylenetetramine g 7 Trichloroacetic acid g1,3,6-naphthalene tn'sulfonic acid, sodium salt g 21 p-Dimethylaminobenzene diazonium chloride, zinc chloride salt g 282,3-dihydroxynaphthalene-6-sulfonic acid, sodium salt g 3 Thiourea g 49Zinc chloride g 28 To separate 165 ml. aliquots of the above stocksolution were added: 7.5 grams of (carboxymethyl) trimethyl ammoniumchloride hydrazide, 6.0 grams of succinhydrazide, 4.0 grams ofcarbohydrazide, and 5.0 grams of acetone semicarbazone. The remainderwas used as a control solution. After the separate solutions had beencoated, dried, exposed, and developed as in Example 5, the followingcolor images were obtained on relatively white backgrounds(Carboxymethyl) trimethyl ammonium chloride hydrazide-purpleSuccinhydrazide-red violet Carbohydrazide-violet Acetonesemicarbazone-violet t is apparent that the described examples arecapable of many variations and modifications Within the scope thepresent invention. All such variations and modifications are to beincluded within the scope of the resent in vention.

What is claimed is:

1. A sheet for the thermal development of a photosensitive diazo layercomprising a photosensitive diazonium compound and a coupler therefor,which comprises:

a support resistant to the scorching effects of heat at the conditionsof thermal development, said support having said diazo layer coatedthereon; and

a thermosensitive base-releasing agent selected from the groupconsisting of: hexamethylene tetramine, thiosemicarbazide, and mixturesof hexamethylene tetramine with one of the following: semicarbazidehydrochloride, carboxymethyl trimethyl ammonium chloride hydrazide,carbohydrazide, succinhydrazide, and acetone semicarbazone coated onsaid support,

whereby heating said coated support to release base in the presence ofsaid layer causes said layer to form a dye.

2. A sheet in accordance with claim 1 in which said agent is intimatelyadmixed with said layer on said support.

3. A sheet in accordance with claim 1 in which said agent is betweensaid support and said layer.

4. A sheet for the thermal development of a photosensitive diazo layercomprising a photosensitive diazonium compound and a coupler therefor,which comprises:

a support resistant to the scorching effects of heat at the conditionsof thermal development, said support having said diazo layer coatedthereon; and

thermosensitive base-releasing hexamethylene tetramine coated on saidsupport in intimate admixture with the diazo layer on said support,

whereby heating said coated support to release base in the presence ofsaid layer causes said layer to form a dye.

5. A sheet for the thermal development of a photosensitive diazo layercomprising a photosensitive diazonium compound and a coupler therefor,which comprises:

a support resistant to the scorching effects of heat at the conditionsof thermal development, said support having said diazo layer coatedthereon; and

thermosensitive base-releasing hexamethylene tetramine coated on saidsupport between said support and said diazo layer.

whereby heating said coated support to release base in the presence ofsaid layer causes said layer to form a dye.

6. A method for thermally developing a photosensitive diazo layercomprising a photosensitive diazonium compound and a coupler therefor,which comprises the steps of:

exposing said layer to image wise actinic radiation; and

heatingsaid layer in intimate contact with a support at C. to C. for afew seconds to form a dye image in said layer, said support beingresistant to the scorching effects of heat at the conditions of thermaldevelopment and coated with a thermosensitive base-releasing agent andsaid agent being a member selected from the group consisting of:hexamethylene tetramine, thiosemicarbazide, and mixtures ofhexamethylene tetramine with one of the following: sernicarbazidehydrochloride, carboxymethyl trimethyl ammonium chloride hydrazine,carbohydrazide, succinhyclrazide, and acetone semicarbazone.

7. A method in accordance with claim 6 in which said agent and the layerare intimately admixed and are coated on the same support.

8. A method in accordance with claim 6 in which said agent is coated onsaid support between said support and said layer.

9. A method in accordance with claim 6 in which said agent and saidlayer are coated on separate supports resistant to the scorching effectsof heat at the conditions of thermal development.

References Cited in the file of this patent UNITED STATES PATENTS2,653,091 Greig Sept. 22, 1953 2,732,299 Morrison Ian. 24, 19562,774,669 Marron et al. Dec. 18, 1956 2,982,675 Kapral May 2, 1961FOREIGN PATENTS 816,601 Great Britain July 15, 1961 215,526 AustraliaFeb. 9, 1961 1,249,913 France Nov. 28, 1960 OTHER REFERENCES Kosar:Photographic Science and Engineering, vol. 5, No.4, July-August 1961,pages 239243.

6. A METHOD FOR THERMALLY DEVELOPING A PHOTOSENSITIVE DIAZO LAYERCOMPRISING A PHOTOSENSITIVE DIAZONIUM COMPOUND AND A COUPLER THEREFOR,WHICH COMPRISES THE STEPS OF: EXPOSING SAID LAYER TO IMAGE WISE ACTNICRADIATION; AND HEATING SAID LAYER IN INTIMATE CONTACT WITH A SUPPORT AT140*C. TO 160*C. FOR A FEW SECONDS TO FORM A DYE IMAGE IN SAID LAYER,SAID SUPPORT BEING RESISTANT TO SCORCHING EFFECTS OF HEAT AT THECONDITIONS OF THERMAL DEVELOPMENT AND COATED WITH A THERMOSENSITIVEBASE-RELEASING AGENT AND SAID AGENT BEING A MEMBER SELECTED FROM THEGROUP CONSITING OF: HEXAMETHYLENE TETRAMINE, THIOSEMICARBAZIDE, ANDMIXTURES OF HEXAMETHYLENE TETRAMINE WITH ONE OF THE FOLLOWING:SEMICARBAZIDE HYDROCHLORIDE, CARBOXYMETHLY TRIMETHOL AMMONIUM CHLORIDEHYDRAZINE, CARBOHYDROAZIDE, SUCCINHYDRAZIDE, AND ACETONE SEMICARBAZONE.